A fire emergency navigation and positioning system and method for a building

Abstract

The present invention discloses a fire emergency navigation and positioning system and method inside a building. The system includes a handheld positioning device, a fire emergency light, a first UWB transceiver and an intelligent sensor. Each handheld positioning device has a UWB positioning tag and a second UWB transceiver; each fire emergency light has a power supply, a display screen and a processor. The first UWB transceiver and the intelligent sensor are installed in each fire emergency light and are connected to the processor and the power supply. The first UWB transceiver is used to send a corresponding signal and its own positioning data to the processor when receiving the UWB signal of the UWB positioning tag; the processor is used to calculate and send the positioning data and environmental data of the handheld positioning device, judge the unobstructed condition of the passage, and control the display screen to indicate the escape route according to the judgment result and the environmental data. The present invention can provide firefighters with the unobstructed condition of the passage inside the building and the distribution of trapped personnel, thereby improving the efficiency of disaster relief.

Description

Technical Field

[0001] The present invention relates to the technical field of fire fighting and navigation positioning, and in particular to a fire emergency navigation positioning system and method inside a building. Background Art

[0002] In life, building fire accidents happen from time to time. According to statistics, in 2018, a total of 237,000 fires were reported nationwide, killing 1,407 people, injuring 798 people, and direct property losses of 3.675 billion yuan have been calculated. Among them, nearly 80% of the deaths were concentrated inside buildings. An important reason why fires cause such a large number of casualties is that the trapped people inside the building and the firefighters outside the building cannot accurately understand the accessible passages inside the building at this time, and cannot clearly determine the safest and fastest escape route and the best rescue route. Specifically:

[0003] (1) In a panic, trapped people can only escape by following the "safety exit" signs on the walls of the building. However, the passage indicated by the "safety exit" may not be the safest and quickest escape route, which prolongs the time that people are trapped in the fire and reduces the possibility of survival. What is more dangerous is that the safety exit and the passage leading to the safety exit may have been damaged or blocked by the fire. The passage indicated by the "safety exit" may directly cause the death of trapped people. (2) External rescue personnel cannot accurately grasp the smoothness of the internal safety passages and ordinary passages at this time, and it is difficult to accurately grasp the distribution of trapped people inside. Therefore, they can only send people to directly enter the building to investigate when the fire is effectively controlled. This method not only brings huge personal safety risks to external rescue personnel, but also easily misses the best rescue time and the best rescue route.

[0004] It can be seen that if we can timely grasp the passage conditions inside the fire building, the distribution of trapped people and the location of rescue workers, and guide them to escape from the fire scene through the safest and fastest passages, this will be of great significance for reducing the economic losses and casualties caused by the fire and improving disaster relief efficiency.

[0005] At present, there are few studies on the detection methods of the distribution of trapped people in the fire scene, the detection methods of the smoothness of the internal passages of the fire building, and the positioning methods of the rescue personnel. The existing methods mainly include the following:

[0006] (1) Use firefighting robots to detect the internal passages of buildings. This method is the most mature method at present. The method is to control the firefighting robot to enter the building through remote control, and send back the front video images through its camera. The operator behind the scenes analyzes the images to determine the degree of damage to the passage and the fire situation, and then makes rescue decisions. This method has obvious advantages and disadvantages: first, the camera is easily affected by smoke; second, the robot can only be used when the fire situation is effectively controlled, which affects the timeliness of rescue.

[0007] (2) Indoor positioning of firefighters based on inertial measurement unit (IMU). Use 6-axis or 9-axis sensors to measure the posture of firefighters, and use the principle of inertial navigation to track the route of firefighters, so as to obtain the real-time position of firefighters and infer the situation of the internal passage of the fire building based on the route of firefighters. This method only directly realizes the positioning of firefighters, and has two major drawbacks: first, firefighters are required to enter the interior of the fire building, which brings great danger to their lives; second, the inertial navigation method has large errors, and the obtained position of firefighters and the situation of the internal passage of the building are not very accurate.

[0008] (3) Indoor positioning of firefighters based on WIFI. This method measures the signal strength (Received Signal Strength Indication, RSSI) of multiple WIFI access points received by firefighters, calculates the distance between them, and finally selects a series of coordinate estimation methods for indoor positioning. This method also has two prominent disadvantages: first, after a building catches fire, most WIFI access points will lose power; second, the RSSI measurement method used in this aspect is an estimation method, and its relative error is extremely large for small-scale indoor positioning.

[0009] It can be seen that the existing methods are unable to achieve reliable indoor navigation and positioning when a building fire occurs. Therefore, it is necessary to study new emergency navigation and positioning technologies for internal building fires. Summary of the invention

[0010] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide an emergency navigation and positioning system for fires inside buildings. The system can indicate safe and quick escape routes for trapped persons by evaluating the degree of damage and obstruction of internal passages, and provide firefighters with information on the unobstructed conditions of internal passages in buildings and the distribution of trapped persons, thereby improving disaster relief efficiency.

[0011] A second object of the present invention is to provide a method for emergency navigation and positioning of fire inside a building.

[0012] The first object of the present invention is achieved by the following technical solution: A fire emergency navigation and positioning system inside a building, comprising: a handheld positioning device for trapped persons and rescuers, a plurality of fire emergency lights distributed on a passage, a plurality of first UWB transceivers and an intelligent sensor, wherein:

[0013] Each handheld positioning device has a UWB positioning tag for emitting a UWB signal and a second UWB transceiver;

[0014] Each fire emergency light has a display screen, a power supply and a processor. The power supply and the processor are located inside the fire emergency light. The display screen is exposed on the surface of the fire emergency light. The display screen and the processor are connected to the power supply respectively, and the display screen is connected to the processor.

[0015] The smart sensor is installed in each fire emergency light and connected to the processor and the power supply. The smart sensor is used to collect environmental data and send the environmental data to the processor;

[0016] Each first UWB transceiver is installed in a corresponding fire emergency light, and the plurality of first UWB transceivers together constitute a building internal navigation system with a plurality of positioning base stations. The first UWB transceiver is connected to the processor and the power supply, and is used to send a corresponding signal and its own positioning data to the processor when receiving a UWB signal;

[0017] The processor is used to obtain the positioning data of the handheld positioning device based on the signal and positioning data of each first UWB transceiver, and send the positioning data and environmental data of the trapped person to the second UWB transceiver of the handheld positioning device of the trapped person and the rescuer through the first UWB transceiver, and judge the unobstructed condition of the channel according to the qualitative change of RSSI between different first UWB transceivers, and control the display screen to indicate the escape route according to the judgment result and environmental data.

[0018] Preferably, the smart sensors include but are not limited to temperature sensors, humidity sensors and pressure sensors.

[0019] Preferably, the processor uses an STM32F103 chip.

[0020] Preferably, the first UWB transceiver and the second UWB transceiver both use DWM1000 modules.

[0021] Preferably, the display screen adopts an LED dot matrix screen.

[0022] The second object of the present invention is achieved by the following technical solution: a method for emergency navigation and positioning of fire inside a building, the method is based on the emergency navigation and positioning system for fire inside a building described in the first object of the present invention, and comprises the following steps:

[0023] S1. The handheld positioning device of the trapped person inside the building sends out a UWB signal through the UWB positioning tag;

[0024] S2, each fire emergency light located in the internal passage of the building, the internal intelligent sensor collects the environmental data of the passage and sends it to the processor; the first UWB transceiver detects the UWB signal in real time, and sends the corresponding signal and its own positioning data to the processor when receiving the UWB signal;

[0025] S3. The processor obtains the positioning data of the handheld positioning device based on the signals and positioning data of multiple first UWB transceivers, and then sends the positioning data of the trapped person and the environmental data of the channel to the second UWB transceiver of the handheld positioning device of the trapped person and the rescuer through the first UWB transceiver, and judges the smoothness of the channel according to the qualitative changes of RSSI between different first UWB transceivers. Finally, according to the judgment result and environmental data, the display screen of the fire emergency light is controlled to indicate the escape route.

[0026] Preferably, the processor uses the TDOA method to obtain the positioning data of the handheld positioning device: first calculate the distance difference between the UWB signal of the handheld positioning device and the first UWB transceiver of each known location, and then calculate the positioning coordinates of the handheld positioning device through the TDOA equation and the positioning data of the first UWB transceiver.

[0027] Preferably, the processor determines whether there is a blocking medium between different first UWB transceivers and the type of the medium according to the qualitative change of the RSSI between different first UWB transceivers, thereby determining the smoothness of the channel:

[0028] If the signal attenuation between two first UWB transceivers reaches 60% and is lower than 100%, it is determined that there is a brick-concrete solid wall between the two first UWB transceivers;

[0029] If the signal attenuation between two first UWB transceivers reaches 100%, it is determined that there is a steel plate between the two first UWB transceivers;

[0030] If the signal attenuation between two first UWB transceivers is less than 10%, it is determined that there is glass, wood or cardboard between the two first UWB transceivers;

[0031] If the signal between two first UWB transceivers is substantially not attenuated, it is determined that there is no blocking medium between the two first UWB transceivers.

[0032] Compared with the prior art, the present invention has the following advantages and effects:

[0033] (1) Based on ultra-wideband (UWB) technology, the present invention designs an emergency navigation and positioning system that can be used indoors in the event of a fire. By adding an intelligent sensor to a fire emergency light and a first UWB transceiver to the fire emergency light, the fire emergency light becomes an indoor positioning base station without affecting the function of the fire emergency light, and a positioning system with decimeter-level positioning accuracy is constructed inside the building. The trapped persons and rescuers can determine their positions and survival status inside the building in real time through a handheld positioning device, and the rescuers can determine the positions and survival status of the trapped persons inside the building in real time through a handheld positioning device, which is conducive to improving the real-time and effectiveness of rescue. The processor can qualitatively analyze whether there is a blocking medium between the fire emergency lights and the type of the medium (brick-concrete solid wall, steel plate, glass / wooden board / cardboard) based on RSSI, so as to judge the smoothness of the passage, so that the display screen can be controlled to indicate a safe, fast and unobstructed escape route according to the judgment result and environmental data, so as to facilitate the escape of the trapped persons and rescuers, thereby effectively improving the efficiency of disaster relief and reducing the economic losses and casualties caused by the fire.

[0034] (2) In the system of the present invention, the processor, the intelligent sensor and the first UWB transceiver are all installed in the fire emergency light and powered by the power supply in the fire emergency light. Therefore, it can be ensured that under fire conditions, the positioning base station function of the system will not fail due to power failure, and there is sufficient power to maintain its normal operation. The protection level of the fire emergency light is IP65, and the power consumption of UWB technology is low, which further ensures the reliability of the system. The system of the present invention can be applied to shopping malls, office buildings, residences, schools and other places, and has a wide range of applications.

[0035] (3) Considering that the positioning distance of the system of the present invention is small and the relative error caused by the precise time synchronization of TOF is large, the present invention uses the TDOA method to calculate the positioning data of the handheld positioning device, and the calculation accuracy and reliability are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a connection diagram of the handheld positioning device for trapped persons and rescuers, the fire emergency light, the first UWB transceiver and the smart sensor.

[0037] Figure 2 Schematic diagram of a building interior navigation system consisting of the first UWB transceiver for multiple fire emergency lights.

[0038] Figure 3 The present invention is a flow chart of the method for emergency navigation and positioning of fire inside a building. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0040] Example

[0041] This embodiment discloses a building internal fire emergency navigation and positioning system. Figure 1 and Figure 2 As shown, it includes: a handheld positioning device 1 for trapped persons, a handheld positioning device 2 for rescuers, a plurality of fire emergency lights 3 distributed on the passage, a plurality of first UWB transceivers 4 and an intelligent sensor 5.

[0042] Each handheld positioning device has a UWB positioning tag for sending UWB signals and a second UWB transceiver. The first UWB transceiver and the second UWB transceiver of this embodiment can both use DWM1000 modules.

[0043] Each fire emergency light has a display screen, a power supply and a processor. The power supply and the processor are located inside the fire emergency light, and the display screen is exposed on the surface of the fire emergency light. The display screen and the processor are connected to the power supply respectively, and the display screen is connected to the processor. In this embodiment, the processor uses an STM32F103 chip, and the display screen uses an LED dot matrix screen. The LED dot matrix replaces the fixed display so as to indicate the escape route.

[0044] The smart sensor is installed in each fire emergency light and connected to the processor and power supply. Since the fire emergency light shell itself is provided with a through hole, the smart sensor can collect the environmental data of the channel. After the smart sensor collects the environmental data, it sends the environmental data to the processor. Here, the smart sensor includes but is not limited to a temperature sensor, a humidity sensor and a pressure sensor. The temperature sensor collects the temperature data of the channel, the humidity sensor collects the humidity data of the channel, and the pressure sensor collects the air pressure data of the channel. These data can facilitate the judgment of the fire condition inside the building.

[0045] Each first UWB transceiver is installed in a corresponding fire emergency light, and multiple first UWB transceivers together constitute a building internal navigation system with multiple positioning base stations to achieve indoor decimeter-level positioning.

[0046] The first UWB transceiver is connected to the processor and the power supply, and is used to send a corresponding signal and its own positioning data to the processor when receiving a UWB signal. The corresponding signal of the first UWB transceiver is used to notify the processor that the first UWB transceiver has detected a UWB signal. According to fire protection requirements, the protection level of the fire emergency light is IP65, and the continuous power supply time is not less than 90 minutes. Therefore, the first UWB transceiver of this embodiment is powered by the battery of the original fire emergency light, which can ensure that under fire conditions, the positioning base station function of the system will not fail due to power failure, and there is enough power to maintain its normal operation. The low power consumption of UWB and the mandatory technical requirements of fire emergency lights also further ensure the reliability of the system.

[0047] The processor is used to obtain the positioning data of the handheld positioning device (i.e., the positioning data of the trapped person) using the TDOA method based on the signal and positioning data of each first UWB transceiver, and send the positioning data and environmental data of the trapped person to the second UWB transceiver of the handheld positioning device of the trapped person and the rescuer through the first UWB transceiver. Therefore, the trapped person can know his current position and the current fire situation of the channel in time, and the rescuer can know the current position of the trapped person and the current fire situation of the channel in time, which facilitates the rescue work.

[0048] Here, the first UWB transceiver specifically sends out the transmission data containing the location data and environmental data of the trapped person in the form of broadcasting, and the transmission data contains the destination address and the transmission source marked with the location data and environmental data, so all the second UWB transceivers can receive the location data and environmental data of the trapped person. Since each handheld positioning device stores its own address, the second UWB transceiver can filter the data according to the address, and only process the data whose destination address is its own address, and can distinguish which location the handheld positioning device / smart sensor of the fire emergency light comes from according to the transmission source in the data.

[0049] The processor is also used to judge the channel smoothness according to the qualitative changes of RSSI between different first UWB transceivers, specifically to judge whether there is a blocking medium between different first UWB transceivers and the type of medium, and then formulate an escape route according to the judgment result and environmental data, so as to control the display screen to indicate the escape route, so as to facilitate the escape of trapped persons and rescuers.

[0050] Based on the above-mentioned building internal fire emergency navigation and positioning system, this embodiment also discloses a building internal fire emergency navigation and positioning method, such as Figure 2 and Figure 3 As shown, the following steps are included:

[0051] S1. The handheld positioning device of the trapped person inside the building sends out a UWB signal through the UWB positioning tag;

[0052] S2, each fire emergency light located in the internal passage of the building, its internal intelligent sensor collects the environmental data of the passage and sends it to the processor; the first UWB transceiver detects the UWB signal in real time, and sends the corresponding signal and its own positioning data to the processor when receiving the UWB signal, the positioning data is as follows Figure 2 The coordinates shown are (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4), (Xn, Yn);

[0053] S3. The processor obtains positioning data of the handheld positioning device according to the signals and positioning data of the plurality of first UWB transceivers.

[0054] Here, although the methods of multi-base station positioning mainly include time of flight ranging (TOF) and time difference of arrival (TDOA), considering that the positioning distance of the present system is small and the relative error caused by the precise time synchronization of TOF is large, the processor of the present embodiment adopts the TDOA method to obtain the positioning data of the handheld positioning device, specifically: first calculate the distance difference from the UWB signal of the handheld positioning device to the first UWB transceiver of each known positioning, wherein the distance from the UWB signal to the first UWB transceiver is, for example, Figure 2 The L1, L2, L3, L4, and L5 shown are then used to calculate the positioning coordinates of the handheld positioning device through the TDOA equation and the positioning data of the first UWB transceiver.

[0055] Then, the processor sends the positioning data of the trapped person and the environmental data of the channel to the second UWB transceiver of the trapped person and the rescuer's handheld positioning device through the first UWB transceiver, and judges the smoothness of the channel based on the qualitative changes in RSSI between different first UWB transceivers. Finally, the processor controls the display screen of the fire emergency light to indicate the escape route based on the judgment result and environmental data.

[0056] According to theoretical calculations and experimental results, different media have different attenuation effects on UWB signals. The attenuation caused by brick-concrete solid walls is 60%, the attenuation caused by steel plates is 100%, and the attenuation caused by glass, wood, and cardboard is less than 10%. Since fire emergency lights are located on both sides of the emergency passage, the processor can determine whether there is an obstruction medium between different first UWB transceivers and the type of medium based on the qualitative changes in RSSI between different first UWB transceivers, thereby determining the smoothness of the passage, that is, the damage.

[0057] Specifically, if the signal attenuation between two first UWB transceivers reaches 60% and is lower than 100%, it is determined that there is a brick-concrete solid wall between the two first UWB transceivers;

[0058] If the signal attenuation between two first UWB transceivers reaches 100%, it is determined that there is a steel plate between the two first UWB transceivers;

[0059] If the signal attenuation between two first UWB transceivers is less than 10%, it is determined that there is glass, wood or cardboard between the two first UWB transceivers;

[0060] If the signal between two first UWB transceivers is substantially not attenuated, it is determined that there is no blocking medium between the two first UWB transceivers.

[0061] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A building internal fire emergency navigation and positioning system, characterized in that: include: Handheld positioning devices for trapped persons and rescuers, multiple fire emergency lights distributed on the passage, multiple first UWB transceivers and smart sensors, among which, Each handheld positioning device has a UWB positioning tag for emitting a UWB signal and a second UWB transceiver; Each fire emergency light has a display screen, a power supply and a processor. The power supply and the processor are located inside the fire emergency light. The display screen is exposed on the surface of the fire emergency light. The display screen and the processor are connected to the power supply respectively, and the display screen is connected to the processor. The smart sensor is installed in each fire emergency light and connected to the processor and the power supply. The smart sensor is used to collect environmental data and send the environmental data to the processor; Each first UWB transceiver is installed in a corresponding fire emergency light, and the plurality of first UWB transceivers together constitute a building internal navigation system with a plurality of positioning base stations. The first UWB transceiver is connected to the processor and the power supply, and is used to send a corresponding signal and its own positioning data to the processor when receiving a UWB signal; The processor is used to obtain the positioning data of the handheld positioning device based on the signal and positioning data of each first UWB transceiver, and send the positioning data and environmental data of the trapped person to the second UWB transceiver of the handheld positioning device of the trapped person and the rescuer through the first UWB transceiver, and judge the unobstructed condition of the channel according to the qualitative change of RSSI between different first UWB transceivers, and control the display screen to indicate the escape route according to the judgment result and environmental data.

2. The building internal fire emergency navigation and positioning system according to claim 1, characterized in that: Smart sensors include, but are not limited to, temperature sensors, humidity sensors, and pressure sensors.

3. The building internal fire emergency navigation and positioning system according to claim 1, characterized in that: The processor uses STM32F103 chip.

4. The building internal fire emergency navigation and positioning system according to claim 1, characterized in that: The first UWB transceiver and the second UWB transceiver both use the DWM1000 module.

5. The building internal fire emergency navigation and positioning system according to claim 1, characterized in that: The display screen uses LED dot matrix screen.

6. A method for emergency navigation and positioning in a building fire, characterized in that: The method is based on the building internal fire emergency navigation and positioning system according to any one of claims 1 to 5, and comprises the following steps: S1. The handheld positioning device of the trapped person inside the building sends out a UWB signal through the UWB positioning tag; S2, each fire emergency light located in the internal passage of the building, the internal intelligent sensor collects the environmental data of the passage and sends it to the processor; the first UWB transceiver detects the UWB signal in real time, and sends the corresponding signal and its own positioning data to the processor when receiving the UWB signal; S3. The processor obtains the positioning data of the handheld positioning device based on the signals and positioning data of multiple first UWB transceivers, and then sends the positioning data of the trapped person and the environmental data of the channel to the second UWB transceiver of the handheld positioning device of the trapped person and the rescuer through the first UWB transceiver, and judges the smoothness of the channel according to the qualitative changes of RSSI between different first UWB transceivers. Finally, according to the judgment result and environmental data, the display screen of the fire emergency light is controlled to indicate the escape route.

7. The method for emergency navigation and positioning of fire inside a building according to claim 6, characterized in that: The processor uses the TDOA method to obtain the positioning data of the handheld positioning device: first calculate the distance difference between the UWB signal of the handheld positioning device and the first UWB transceiver of each known location, and then calculate the positioning coordinates of the handheld positioning device through the TDOA equation and the positioning data of the first UWB transceiver.

8. The method for emergency navigation and positioning in a building interior fire according to claim 6, characterized in that: The processor determines whether there is a blocking medium between different first UWB transceivers and the type of the medium according to the qualitative change of the RSSI between different first UWB transceivers, thereby determining the smoothness of the channel: If the signal attenuation between two first UWB transceivers reaches 60% and is lower than 100%, it is determined that there is a brick-concrete solid wall between the two first UWB transceivers; If the signal attenuation between two first UWB transceivers reaches 100%, it is determined that there is a steel plate between the two first UWB transceivers; If the signal attenuation between two first UWB transceivers is less than 10%, it is determined that there is glass, wood or cardboard between the two first UWB transceivers; If the signal between two first UWB transceivers is substantially not attenuated, it is determined that there is no blocking medium between the two first UWB transceivers.

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